These is an increasing use of cans made of various metals, and proper disposal thereof has become a significant concern. In order to minimize littering of the cans and further reduce the consumption of energy and raw materials, it is advisable to re-use the materials from which the cans are made after the contents of the cans have been expended. With respect to cans made of different metals, it is usually necessary that the metals be separated before reprocessing or remelting of the cans is feasible. In the case of a beverage can having a steel body with tin plating, a steel lid and an aluminum lid, the aluminum lid must be removed prior to subsequent reprocessing of the remaining portions of the can. Failure to remove the aluminum and tin from the steel results in an important loss of those two metals when the steel is melted. Additionally, the presence of tin with the steel is normally unacceptable for proper reprocessing. Similarly, the aluminum cannot be successfully reprocessed without removal of the steel and tin.
Generally speaking, devices have been developed for recovering the different metals of cans by means of a crushing or a shredding operation, together with additional processing steps involving magnetic, electrostatic, inductive, screening, or density applications. As can be appreciated, these methods are cumbersome and expensive.